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[scout1]

I pulled the 300wsm out of the safe last night after a year, loaded 10 rounds and took it to the range for a load test.
All rounds were loaded to the same spec. 65.3 grns of IMR-4831 under a 155 Scenar, with a COAL of 2.93
The first 5 grouped in one hole .333 at 100 yards and clocked the chrono at an average of 3150 fps with an ES of 65 fps. The low was the first shot at 3105

I moved the target back to 200 yards at shot the second group of five, same exact load. It averaged 3270 fps and grouped in .755 The ES on this group was 28 fps

I'm trying to get ready for a local tournament in the morning and cant make heads or tails of this 120 fps swing. I am just in the lands with my 2.93 COAL so I bumped my shot start pressure up to 8500 psi in QL, set my temperature at 97 degrees, input an average of 10 bullet weights, my brass is sorted to within 1 grain and the program tells me I should be around 3110 fps so thats a 160 fps swing.

I didnt adjust the scope and had exactly two inches difference in impact between the l00 and 200 yard groups using the same aiming point.
Has anyone got any ideas.

 

[scout1]

Well, I must have had bad light or something yesterday when I was chronographing the load. I had the Bullet flight program on my I-pod and had input a speed of 3240 fps based off of the info I fed into Q.L.from Fridays test session. I had dropped the charged based on the shooting conditions for this mornings match from 65.3 grns to 64.8 grns in order to match a barrel node from Long's paper. Needless to say I was way off. My first sighters at 600 yards were approx 13' low. Working the ballistics backwards that put me at 3050 instead of 3240 fps with an 11 moa come up insted of a 9.5 moa come up.

I guess I need a new chronograph if I expect to get accurate feedback from Q.L. As the old saying goes, Crap in, crap out.

I still cant count the day as a total loss. The info gained let me know where I was at, and where I need to go to tighten things up. The Kreiger barrel didnt let me down, even with a load outside of a node I still managed 3 1/2" at 600. Not BR standards but good enough for me today.